Saturday, 31 August 2013

I had agreed to do a weekly dawn count of the Great Egrets Ardea alba roosting on the Speed River at the area known as the Hespeler Mill Pond, so at 05:29 I was in position to wait for sunup. As soon as there was even a hint of light I could see the egrets lined up, looking for all the world like a white picket fence sticking out of the water. In all, there were twenty-one birds roosting there, resembling stoic sentinels of the night.

As it got lighter they started to fidget, preen, flap their wings, move around and squabble a little. Many flew off to the east and by the time I left at 07:00 only five birds remained, along with several Great Blue Herons Ardea herodias.

Later in the morning I stopped by Laurel Creek and found the Great Blue Heron shown below.

A Green Heron Butorides virescens has been frequenting the area for the past couple of weeks but it was nowhere to be seen this morning.

It was quite heavily overcast and the following scene looked especially serene on a grey day.

A juvenile Pied-billed Grebe Podilymbus podiceps was sticking close to one of its parents.

And a juvenile Cedar Waxwing Bombycilla cedrorum was perfecting its flycatching skills.

I moved on to the little wetland on Beaver Creek Road mentioned in an earlier post. This tiny area, barely an acre I would guess, has been incredibly productive of late and today was no exception. It is surrounded by houses on three sides and by the road on the fourth and as can be seen from the photographs below is densely vegetated. This makes it difficult at times to get a decent shot of the birds since the camera constantly tries to focus on intervening leaves or branches.

I was absolutely surprised to see two Great Egrets feeding in the marsh. It appears to be a bumper year for frogs no doubt making the location attractive for all species of heron

Earlier in the week I had seen two immature Black-crowned Night Herons Nycticorax nycticorax roosting in the wetland; today an adult bird was present.

Two nights ago we were able to watch a Sora Pozana carolina at Laurel Creek for about ten minutes, so it has been a productive week at the wetlands, truly one of my favourite habitats.

Thursday, 29 August 2013

The Cyanogenic Glycoside Amygdalin Does Not Deter Consumption of Ripe Fruit by Cedar Waxwings

Cyanogenic glycosides are common secondary compounds in ripe fruits that are dispersed by birds. These substances are toxic to some mammals. We examined the repellent effect of amygdalin, a cyanogenic glycoside, on Cedar Waxwings Bombycilla cedrorum. Amygdalin did not reduce food ingestion in Cedar Waxwings, even at relatively high concentrations. In addition, these birds did not exhibit preference for amygdalin-free over amygdalin-containing fruit. Cedar Waxwings given artificial food that contained four times the amount of amygdalin found in some wild fruits ingested the equivalent of 5.5 times the oral lethal dose for rats in 4 hr without exhibiting any external signs of toxicity. Amygdalin ingestion appeared to have a negative effect on nitrogen retention and food assimilation. However, when nitrogen retention and food assimilation were recalculated assuming that all amygdalin ingested was excreted intact, these negative effects disappeared. The presence of large amounts of unhydrolyzed amygdalin in the excreta of waxwings fed on amygdalin-laced food confirmed our conjecture that amygdalin was excreted intact. We hypothesize that in Cedar Waxwings, amygdalin is absorbed in the intestine but is not hydrolyzed by endogenous enzymes and thus is excreted intact in urine. The apparent lack of repellent effects of amygdalin in Cedar Waxwings suggest that toxicity data for rats and humans may be a poor predictor for the deterrent effect of fruit secondary compounds on frugiverous birds. Many hypotheses that have been posed to explain the presence of secondary compounds in ripe fruit assume that these substances have repellent/toxic effects on avian seed dispersers. For some compounds, such as amygdalin and other cyanogenic glycosides, this assumption may not be valid.

Wednesday, 28 August 2013

For the past two years, I have observed a family of Common Mergansers along the Speed River, and have been able to watch their development. By this time of the year the young are essentially the same size as the adults, although still dependent on parental care. Obviously these birds are breeding along the river or very close to it.

The following terrific pictures were taken by Fred Urie, a dedicated devotee of this section of the river, and I appreciate very much his permission to use them on my blog.

Tuesday, 27 August 2013

There is a very small wetland next to some upscale houses on Beaver Creek Road and this location is rapidly becoming one of my favourite birding spots. It is quite remarkable how many species I have seen there. At this time of year, with the vegetation on the sidewalk and in the marsh so high, it does not afford the best viewing opportunities, but it is still very worthwhile checking out.

This morning I watched two juvenile Black-crowned Night Herons fly in and quickly ensconce themselves in a distant part of the marsh where visibility from the sidewalk is not the best. I was able to get this picture of one of them snoozing, and it was certainly encouraging to see two healthy young birds.

Monday, 26 August 2013

A visit to Laurel Creekthis evening offered up the very rewarding spectacle of a total of seven Pied-billed Grebes, including an adult feeding four young. It was interesting to watch one juvenile in particular. It seemed to have an uncanny knack of figuring out where the parent would emerge from its dive and would consistently position itself close to that spot so it received the greatest share of the fish brought to the surface by the adult. All four chicks were fed to be sure, but the one made sure that it had first dibs on the food.

In the picture below the adult is offering a fish to one of the youngsters and an adult and an immature Red-winged Blackbird Agelaius phoeniceus can be seen in the picture. The Red-winged Blackbirds were arriving by the hundreds to roost in the marshes.

Four juveniles together

Adult and two juveniles

This adult was farther out on the lake and is seen preening and swimming. The reflection in the sunlit water is quite striking

This is where the Spotted Sandpiper was before I depressed the shutter!

An adult male American Goldfinch Carduelis tristis was high atop a cedar.

And this American Crow Corvus brachyrhynchos surveyed the world from its lofty perch.

Friday, 23 August 2013

Once in a while someone
does a nice job of describing a Canadian, this time it was an Australian
dentist.

An Australian definition of a Canadian - in case anyone asks you who a Canadian is.

You probably missed it in the local news, but there
was a report that someone in Pakistan had advertised in a newspaper an offer of
a reward to anyone who killed a Canadian - any Canadian.

An Australian dentist wrote the following editorial
to help define what a Canadian is, so they would know one when they found one.

A Canadian can be English, or French, or Italian,
Irish, German, Spanish, Polish, Russian or Greek. A Canadian can be Mexican,
African, Indian, Chinese, Japanese, Korean, Australian, Iranian, Asian, Arab,
Pakistani or Afghan. A Canadian may also be a Cree, Metis, Mohawk, Blackfoot,
Sioux, or one of the many other tribes known as native Canadians. A Canadian's
religious beliefs range from Christian, Jewish, Buddhist, Muslim, Hindu or
none. In fact, there are more Muslims in Canada than in Afghanistan. The key
difference is that in Canada they are free to worship as each of them chooses.
Whether they have a religion or no religion, each Canadian ultimately answers
only to God, not to the government, or to armed thugs claiming to speak for the
government and for God.

A Canadian lives in one of the most prosperous
lands in the history of the world. The root of that prosperity can be found in
the Charter of Rights and Freedoms which recognize the right of each person to
the pursuit of happiness.

A Canadian is generous and Canadians have helped
out just about every other nation in the world in their time of need, never
asking a thing in return. Canadians welcome the best of everything, the best
products, the best books, the best music, the best food, the best services and
the best minds. But they also welcome the least - the oppressed, the outcast
and the rejected.

These are the people who built Canada. You can try
to kill a Canadian if you must as other blood-thirsty tyrants in the world have
tried but in doing so you could just be killing a relative or a neighbour. This
is because Canadians are not a particular people from a particular place. They
are the embodiment of the human spirit of freedom. Everyone who holds to that
spirit, everywhere, can be a Canadian.'Keep your stick on the ice'

Sunday, 18 August 2013

It was exciting, while birding at Princess Point in the afternoon (following a morning at Ellacott Landing) to discover a White Pelican. I say discover in the widest possible sense, realizing that the bird had already been seen by others. It was feeding with a large number of Double-crested Cormorants Phalacrocorax auritus and Ring-billed Gulls Larus delawarensis. There was evidently a large shoal of fish in the area for all the birds were feeding virtually non-stop, including the pelican which could be seen dumping the water from its pouch and manipulating the fish down its gullet.

The picture is taken from far away ( I was on one side of the bay, the bird was on the other) but I feel that even this low grade picture is worth posting to memorialize this great sighting.

Many of the cormorants were much closer; thereby a little more cooperative photographically.

Fred Urie and I spent about an hour and a quarter this morning checking the activity on the Speed River accessible from Ellacott Lookout. It is at this time of year the bird population, especially shorebirds, can change almost by the hour.

View from Ellacott Lookout across the Speed River

There was a very agreeable range of shorebirds, including a crisp, juvenile Baird's Sandpiper Calidris bairdii and a Short-billed Dowitcher Limnodromus griseus. Many were quite distant and not amenable to photographs, however. It will help to click on these pictures to view a larger image.

Stilt Sandpiper with Two Solitary Sandpipers

Most impressive, perhaps, was the sheer number of Great Egrets Ardea alba. We counted eighteen, a new high for both Fred and me at this location.

The following picture shows Canada Geese Branta canadensis, Lesser Yellowlegs Tringa flavipes, of which there were many, Ring-billed Gulls and if you click to enlarge the picture you will see a Semipalmated Plover Charadrius semipalmatus behind the leftmost Canada Goose.

Wednesday, 14 August 2013

After dinner tonight Miriam and I decided to go over to Laurel Creek to see what we could find. It was a very pleasant evening to stroll beside the lake and we came across this huge Snapping Turtle Chelydra serpentina. As you can see it had hitched itself out of the water and was astride a log, giving its carapace a kind of odd look.

Several Cedar Waxwings Bombycilla cedrorum were displaying odd rictal bristles which I can't recall ever having noticed before. You will need to click on the picture to enlarge it to see this feature.

This Pied-billed Grebe Podilymbus podiceps proved difficult to photograph, diving every time we got the camera on it. Finally we were successful!

Tuesday, 13 August 2013

It has been widely reportedin ornithological journals that all aerial insectivores are suffering serious declines across the continent. Chimney Swifts face the additional problem that many old chimneys are being demolished and breeding habitat is being eliminated.

For the past couple of years we have been monitoring a Chimney Swift roost at Dickson Public School in Cambridge, ON. There is a suitable chimney on this structure which dates back to the mid eighteen-eighties, and it has been well used over the time that we have kept vigil at the site.

This year all that seems to have changed. Two nights ago I watched from around 19:00 to just after 21:00 and saw only nine Chimney Swifts. By this time last year numbers had swelled to more than a hundred. Last night, by 20:00 I had seen but one swift. Bill Read, the single most dedicated watcher in this area, came by and suggested we move to downtown Cambridge, close to the Grand River, where several other chimneys still exist. This is mere seconds away from the Dickson Street School for a rapidly flying Chimney Swift. The activity was a little better but we still counted a disappointing seventeen swifts for the night.

What has happened I am unable to say, but these numbers do not bode well for Chimney Swifts in southern Ontario. It is hard to believe that the Dickson School chimney has simply been abandoned considering that by the end of August last year almost five hundred swifts were entering to roost for the night. Nothing about the chimney has changed and the nine swifts I saw on Sunday night did indeed go into the chimney for the night.

On a little happier note, we saw our first two migrating Common Nighthawks Chordeiles minor for the year and after dark we checked the Great Egret Ardea alba roost along the banks of the Grand River and were very happy to note eleven birds settled in a tree at bank side.

Monday, 12 August 2013

This juvenile House Sparrow has developed a feeding strategy which obviously works. The young bird has some difficulty getting inside the squirrel exclusion cage of the feeder and comically eases itself in from the top, and by part fluttering and part free falling it gets to the tray at the bottom. There it simply stations itself at the feeding port and feeds non-stop until it is full. It often falls asleep right there, only to resume feeding when it awakens. It's a smorgasbord on demand I guess!

Recently there seems to have been a bit of an explosion of Cedar Waxwings, with many birds feeding young. At this time of the year it seems that they take to flycatching more than is perhaps observed in other months and several birds were actively engaged in this behaviour at Laurel Creek. The insect swarm above the water was plainly visible to the naked eye, no doubt making easy pickings for the waxwings.

Sunday, 11 August 2013

Wow, these sparrows have chosen lodgings deemed to be the President's choice! Does it follow that they are occupying the presidential suite? Looks like the standard of housekeeping is not quite up to par! These pictures were taken at the Zehr's store at Fischer-Hallman Road and Erb Street in Waterloo.